Outline

Objective: Hippocampal atrophy associated with hippocampal sclerosis (HS) in patients with pharmacoresistant temporal lobe epilepsy (TLE) may be associated with the atrophy of neocortex in the area of the anterior temporal lobe. The aim of the study was to compare the volume of the anterior temporal lobe equilateral to the epileptogenic zone to the contralateral side.

Methods: 1,5T high resolution MRI images (2mm slice thickness) were obtained in 15 subjects with TLE and histological evidence of HS. The volume of the anterior temporal lobe was measured by MRI volumetry. The posterior boundary was arbitrarily set at the first slice with temporal stem to be seen. The measurement was performed semi-automatically using the INSIGHT-SNAP software. To assess reliability, the intraindividual variability of the measurement was assessed in 10 subjects. The Wilcoxon signed rank was used for statistical analysis.

Results: The anterior temporal lobe volume on the side equilateral to the epileptogenic zone was significantly reduced in comparison with the contralateral side (p<0.05; 13.4Â±3.8cm3 versus 15.2Â±3.5cm3). The intraindividual variability of the measurement was 3.6%.

Conclusions: Pharmacoresistant temporal lobe epilepsy with hippocampal sclerosis is associated with the atrophy of the anterior temporal lobe equilateral to epileptogenic zone, which can be reliably assessed by MRI volumetry as a part of presurgical evaluation.